Windows PCs on different workgroups can see each other

I have all of the computers and servers here all set to a different workgroup than the standard Windows one. I just noticed that a Vista laptop I'm working on, which I connected to the network for Internet access and which is on the standard Windows workgroup is able to see all of the computers and servers on my private workgroup and access the files on the nonencrypted and non-password protected folders.

Am I missing something here? Is this because the computers are on the same network? Can two computers connected to the same network but in different workgroups see and access each other?

 

If two computers are on the same network without any form of logical separation they can access any resource each other provide.

If you want computers on the same network but need to restrict access between them you need to setup VLANs.

 

The idea of workgroups is to do nothing more than that, create different workgroups so one group of users knows that their resources are in that place (Marketing, Accounting, etc)

 

Okay thanks guys! I've never had different workgroups here before (only changed the workgroup to a private name very recently) so I didn't realize this until now. It's not necessary that I have the local machines on a VLAN here, although there is a set of ports in the workshop that are all on a VLAN for connecting infected machines to the Internet "safely" without infecting my own network.

Thanks for the help, rep for all